Water heater

ABSTRACT

A water heater comprising a cylindrical water tank having a gas burner below it and a flue pipe passing through the tank for heating the water. The tank is enclosed in a square sectioned housing having an air inlet to which air from outside the building can be fed. An air intake duct (which leads to the outside of the building) is connected to the air inlet of the heater and is of sufficiently large diameter to allow the flue pipe to pass coaxially through it with sufficient space between the flue pipe and the air intake duct for the supply of combustion air to the burner.

United States Patent Carter [451 May 2,1972

[54] WATER HEATER [21] Appl.No.: 21,617

[56] References Cited UNITED STATES PATENTS McCorquodale ..126/85 BUX Tustin et a]. ..236/92 C FOREIGN PATENTS OR APPLICATIONS 1,157,755 11/1963 Germany ..126/85 B Primary Examiner-Charles J. Myhre Attorney-Rogers, Bereskin & Parr [57] ABSTRACT A water heater comprising a cylindrical water tank having a gas burner below it and a flue pipe passing through the tank for heating the water. The tank is enclosed in a square sectioned housing having an air inlet to which air from outside the building can be fed. An air intake duct (which leads to the outside of the building) is connected to the air inlet of the heater and is of sufficiently large diameter to allow the flue pipe to pass coaxially through it with sufficient space between the flue pipe and the air intake duct for the supply of combustion air to the burner.

2 Claims, 3 Drawing Figures Patented May 2, 1972 3,659,560

3 Sheets-Sheet l INVENTOR. WI LFRED G. CARTER Patented May 2, 1972 3,659,550

3 Sheets-Sheet Z INVENIOR. WI LFRED G. CARTER WATER HEATER This invention relates to a gas water heater of the kind which draws air for combustion from outside the building in which the heater is contained.

In domestic gas water heaters of the above kind (hereinafter called heaters) air is drawn to the heater from outside the building to avoid consumption of the oxygen in the building and to ensure free flow of air to the heater. The air is normally brought into the building through an air intake pipe which enters the building near the ceiling of the room containing the heater, and thence proceeds to a burner at the base of the heater. The air intake pipe may become quite hot due to its proximity to the burner and it is frequently located between the heater and the external wall so that it is relatively out of sight and reach. Such a heater is normally not suitable for use in a confined space, such as a corner of a room. This arrangement results in waste of floor space since the heater itself must be spaced from the wall sufi'iciently to accommodate the air intake pipe.

Domestic heaters also commonly have a pressure/temperature control valve (commonly called a PT valve) to which is connected an overflow pipe for allowing water to escape from the heater if the pressure and/or the temperature of the water in the heater exceeds a predetermined setting. The overflow pipe normally extends down the side of the heater towards the floor so that hot water would be discharged on the floor if the PT valve opens. Although the PT valves of domestic heaters rarely open, the conventional overflow pipe arrangement still presents a possible nuisance or hazard which would be better to avoid.

The heater of the present invention can stand flush against an external wall and can be enclosed on three vertical sides by walls of the room without overheating at any point. The heater can usually be installed with no air ducting visible from inside the building, and the heater overflow pipe is hidden and leads to the outside of the building, where it can safely discharge hot water if necessary.

In a preferred form, the present invention comprises a conventional cylindrical water tank having a gas burner below it and a flue pipe passing through the tank for heating the water. The tank is enclosed in a square sectioned housing having an air inlet to which air from outside the building can be fed. An air intake duct (which leads to the outside of the building) is connected to the air inlet of the heater and is of sufiiciently large diameter to allow the flue pipe to pass coaxially through it with sufficient space between the flue pipe and the air intake duct for the supply of combustion air to the burner. An overflow pipe from a PT valve of the heater also passes through the air intake duct to the outside of the building. When the burner is ignited it draws in air from outside the building through the air intake duct to the housing, and the air then passes through the spaces between the water tank of the heater and the walls of the housing (i.e. at the inside corners of the housing). The flue gases from the burner leave the tank through the flue pipe which discharges to the atmosphere outside the building.

In drawings which illustrate a preferred embodiment of the invention:

FIG. 1 is a perspective view of the heater according to the invention;

FIG. 2 is a partially sectioned view on line 2--2 of FIG. 1; and

FIG. 3 is a sectional view on line 3-3 of FIG. 2.

Reference is first made to FIG. 1 which shows a gas water heater generally indicated by the reference numeral standing on a floor 11 next to an outside wall 12. The heater 10 has a housing 13 of preferably square cross-section, which is provided with a front control cover 14 and a top cover'16 for providing access to internal connections of the heater. A cold water inlet pipe 18 and a hot water outlet pipe 20 pass through the top of the housing 13 near the wall 12. The front of the housing may be provided with a peripheral ornamental strip 22 and the heater 10 is supported on three adjustable feet 24 (only one of which is shown).

Referring now to FIG. 2, the housing 13 contains a conventional cylindrical hot water tank 30 fitted with a gas burner and the usual associated controls (not shown), a burner opening 32 through which air for combustion is drawn, a flue outlet pipe elbow 34 and insulation 36 which is attached to the tank 30 by several steel straps 38. Three spaced apart brackets 40 (two of which are shown) are welded to the underside of the tank 30 and each bracket is provided with a threaded opening for receiving the feet 24 which pass through openings in the bottom of the housing 13. Flue gases are expelled from the heater through a flue pipe 44 connected to the internal flue (not shown) of the heater through the elbow 34. The flue pipe 44 passes coaxially through an opening formed in the wall 12.

The outer end of the flue pipe 44 terminates at a vent cap 46 affixed to the outside of the building. The vent cap 46 has an outer bafile 48, an intermediate bafile 50 and an inner baffle 52. The baffles 48, 50 and 52 are rigidly supported in spaced parallel relation by at least two pillars 51. The baffle plate 52 is formed with a central opening from which there extends an air inlet duct 53 consisting of a short cylindrical duct 54 which is attached to the inner bafile plate 52 and a somewhat longer duct 56 which extends from an air inlet opening 57 formed in the rear wall of the housing 13, through the opening in the wall 12. The duct 56 telescopes in the duct 54. The flue pipe 44 is coaxial with the duct 53 and is sufficiently spaced from the inner wall thereof to provide a sufficient flow of air for combustion from the outside of the building.

The vent cap 46 provides two distinct passages. First, flue gases discharged from the flue pipe 44 are discharged between the outer baflle and the intermediate baffle 50. Second, an air inlet path is formed between the bafile plates 50 and 52 to allow fresh air to be drawn through the air inlet duct 54 into the housing 13. The air then flows through comer spaces 58, 60, 62 and 64 (FIG. 3) between the tank 30 and the housing 13 to the burner opening 32. The incoming air passing through the housing 13 helps to keep the housing 13 cool so that the housing walls do not exceed stipulated temperature limits.

Hot water from the tank 30 reaches the water outlet pipe 20 through a T-connector 66 to which is also attached a PT (safety) valve 68 having an overflow pipe 70. The overflow pipe 70 leads to the vent cap 46 through the ducts 54, and 56. If the PT valve 68 opens, the escaping hot water will pass through the overflow pipe 70 and be discharged outside the building.

The tank 30 is supported in fixed position in the housing 13 by any convenient means. The housing 13 may be made strong enough to support the tank 30 while the heater 10 is transported, or the housing 13 may be designed to be placed about the tank 30 after the tank 30 is positioned in a building. The housing 13 should be quite air-tight when assembled in place about the tank 30 except for the air inlet opening 57 with which the air inlet duct 56 communicates.

It is preferable to make the housing 13 just large enough to contain the insulated tank 30 to minimize the required floor space for the heater 10. However, the housing 13 may have any convenient configuration consistent with allowing sufficient flow of air between the housing 13 and the tank 30.

What I claim as my invention is:

1. A hot water heater comprising:

a housing having a substantially square horizontal cross-section for positioning against an outside wall of a building and including an air inlet adjacent the top rear of the housing, the housing being substantially sealed except for said air inlet;

a duct connected to the air inlet to supply air into the housing, the duct being adapted to pass through the outside wall so that air is inspired from outside the building into the housing;

a cylindrical hot water tank positioned inside the housing and coupled to the housing, said tank having burner means positioned below the water heater for controllably heating water in the tank;

a flue pipe for venting flue gas from said burner, the flue a vent cap attached to respective outer ends of the flue pipe 5 pipe including a portion passing through the duct and spaced from the walls of the duct to carry flue gases outside the building;

and the duct and including baffles to deflect outgoing flue gases away from incoming air; and

the housing being proportioned so that the walls of the housing have a width substantially equal to the outside diameter of the water tank plus a relatively small clearance to facilitate assembly whereby each of the overall width and depth dimensions of the hot water 

1. A hot water heater comprising: a housing having a substantially square horizontal cross-section for positioning against an outside wall of a building and including an air inlet adjacent the top rear of the housing, the housing being substantially sealed except for said air inlet; a duct connected to the air inlet to supply air into the housing, the duct being adapted to pass through the outside wall so that air is inspired from outside the building into the housing; a cylindrical hot water tank positioned inside the housing and coupled to the housing, said tank having burner means positioned below the water heater for controllably heating water in the tank; a flue pipe for venting flue gas from said burner, the flue pipe including a portion passing through the duct and spaced from the walls of the duct to carry flue gases outside the building; a vent cap attached to respective outer ends of the flue pipe and the duct and including baffles to deflect outgoing flue gases away from incoming air; and the housing being proportioned so that the walls of the housing have a width substantially equal to the outside diameter of the water tank plus a relatively small clearance to facilitate assembly whereby each of the overall width and depth dimensions of the hot water heater approximates the outside diameter of the water tank and four corner spaces are formed between the upright corners of the housing and the water tank to permit ingoing air to move downwardly from the air inlet to the burner means.
 2. A hot water heater as claimed in claim 1 and further comprising a pressure/temperature safety valve coupled to the water tank, and an overflow pipe coupled to the safety valve and passing outwardly through the air duct for carrying overflow water in emergency conditions to a location outside the building. 